Scientific studies show that there can be around 4000 chemicals in cigarette smoke. They can be breathed in by anyone near a smoker. They can also stick to clothes, hair, skin, walls and furniture. Try wiping a clean cloth on a window near where someone has been smoking and you will see what you could be breathing in.

Some of these chemicals are:

tar - which has many chemicals in it some of which cause cancer

carbon monoxide - reduces the amount of oxygen in blood - so people can develop heart disease (the amount of carbon monoxide is not enough to cause any immediate effects in passive smokers (such as feeling tired), but over a long time the effects can worsen heart disease)

Talk to your parent or caregiver about passive smoking. Tell them it is now illegal in South Australia to smoke in a car if there are children in the car too, and that it is also illegal to smoke in sports venues and outside eating areas at hotels or cafes.

If your parent or caregiver smokes, ask if they can make the house and car smoke-free zones.

In Australia there are now warnings on cigarette packets about the dangers of smoking.

Most public places are no smoking areas - including playgrounds, sports venues, bus stops and outdoor eating areas.

Many countries have organisations like QUIT which will help people to give up smoking.

Cigarette advertising is no longer allowed in many parts of the world.

Many schools run anti smoking programs.

There are anti smoking advertisements on TV, in newspapers and on cigarette packets.

You have to be 18 years old to buy cigarettes in many countries.

In South Australia it is illegal to smoke in cars where there are children. Smoking is banned within 10 metres of children's public playgrounds. Smoking is also banned in any bus, train or taxi shelter. There is a fine of $75 to $200.

"If you are near smokers, you are smoking too. Help your family to work out how to have a smoke free home. If you live in South Australia, see if your school has copies of the 'Smoke free home and car' booklet, which can give you ideas about how to change smoking habits in your home."

We've provided this information to help you to understand important things about staying healthy and happy. However, if you feel sick or unhappy, it is important to tell your mum or dad, a teacher or another grown-up.